Why doesn't the sea evaporate?

Answer 1

The seas and oceans evaporate constantly. The evaporated water condenses into clouds to cause rainfall over oceans and land. Rivers carry water back to the oceans.

The atmosphere can only hold a small percentage of the world's water at a time, so there is no danger of oceans drying up, but smaller bodies of water can dry up. If an area has no replenishment by rain or stream flow, it will eventually become desert as in Death Valley for example or, if evaporation exceeds inflow, a brine sea forms, as in the Great Salt Lake.

Not all the water is recycled this way! About 4% of the earth's water is held as ice in the Antarctic and Greenland glaciers. As glaciers grow, ocean levels must drop and vice-versa.

Since the average depth of the oceans is (according to the oceanographers) about 4000 m, it follows that if all the glacier ice melted, the ocean depth would increase by 4000m x .04 = about 160 metres. Of course, the continents do not have 160 m high ocean cliffs, so water would spread out over low lands. An 80 metre overall rise is a bandied figure. Well worth further study.

Answer 2

Because the oceans and seas cover such a large proportion of the Earth's surface, over 70%, large scale evaporation is able to occur